Fig. 2.
Concentration and voltage dependence of sodium channel modulation in HEK-293 cells. A: peak Na+ current (INa) amplitude, evoked by steps from −80 mV to −10 mV, was normalized to control and plotted versus drug concentration. Data points represent means ± SE for n = 4–7 cells. Curves represent best fits to the data using the single-site saturation equation given in methods. Half-maximal inhibition (IC50) values were 70, 53, 4, and 10 μM for SKF-10047(▴), pentazocine (▾), haloperidol (⧫), and DTG (▪), respectively. B: INa amplitude was determined for steps to different voltages, in the absence (control) and presence of 100 μM SKF-10047, (+)-pentazocine, and haloperidol. INa recorded in the presence of drugs was normalized to controls. Data points represent means ± SE for n = 3 cells.